The solution is to allow physical loops, but create a loop-free logical topology using link aggregation, shortest path bridging, spanning tree protocol or TRILL on the network switches.
It may then incorrectly direct traffic for that MAC address to the wrong port, effectively causing this traffic to be lost, and even causing other switches to incorrectly associate the sender's address with a wrong port as well.
In a redundant switched network it is possible for an end device to receive the same frame multiple times.
[citation needed] Routing loops are tempered by a time to live (TTL) field in layer-3 packet header; Packets will circulate the routing loop until their TTL value expires.
No TTL concept exists at layer 2 and packets in a switching loop will circulate until dropped, e.g. due to resource exhaustion.